Satellite solar cells would capture the sun's rays 24 hours a day, without fear of cloudy mornings or dark nights. The orbiters then convert this solar power to radio-frequencies that transmit to ground stations in Fresno County, Calif. Once received, the radio energy would change into electricity and flow into the grid.

Such a plan has been accepted by scientists for years. A 2007 Pentagon study concluded that satellite-solar power was feasible, yet significantly more expensive than current energy sources. But PG&E and partner Solaren, a California start-up, claim that their costs will be comparable to rates for other lines of renewable power. They would not give specifics.

"While a system of this scale and exact configuration has not been built, the underlying technology is very mature and is based on communications satellite technology," Solaren CEO Gary Spirnak said in an interview published by PG&E. "For over 45 years, satellites have collected solar energy in Earth orbit via solar cells, and converted it to radio-frequency energy for transmissions to Earth-receive stations."

The power company now turns to state regulators for approval on the 15-year deal with Solaren. Once up and running, the system should produce 800 gigawatt-hours of electricity in the first year, "and 1,700 gigawatt-hours for subsequent years," reports MSNBC. "The larger figure is roughly equal to the annual consumption of 250,000 average homes."